Milepost 237.2 – Eastbound Between Exit 234 and 239
County: Mahoning How it got its name
DQ Grill & Chill with Orange Julius
In eastern Ohio, about seven miles south of the Glacier Hills Service Plaza, lies a low range of hills marking the southern limits of the last advance of the great glacier which pushed down from the polar regions more than 15,000 years ago. Great quantities of rock and gravel were scraped from the solid bedrock, carried along in the ice flow and left standing in a heap when the glacier melted, forming “terminal moraines,” as they are called by the geologists – in other words, “glacier hills.”
In pushing south, the ancient glaciers changed the whole face of the land. They scooped out the areas that are now the Great Lakes. They forced the Allegheny River to flow southward, where it met the Monongahela, and the two formed the Ohio River. Moving across the land the ice sheets scraped off the hills like a giant bulldozer and filled up valleys with the scrapings. That explains why so much of the surface of Ohio is fairly level. At the same time, the ice block forced many streams to find new outlets, thus creating some of the state’s beautiful gorges, such as those of the Chagrin River near Chagrin Falls and of the Licking River new Newark.
The presence in Ohio soil of rock materials not found in the bedrock of Ohio testifies to the distance which debris must have been carried. Remnants of pink granite and hard quartzite are found in Ohio 500 miles south of the bedrock ledges in southern Quebec from which they are believed to have been sundered.
As the glacier inched slowly across Ohio, it pulverized the rocks and mixed them with sand and clay, resulting at length in the deep fertile soil which makes Ohio one of the nation’s leading agricultural states. A very last re-advance of the ice into northern Ohio about 14,000 years ago plowed up the clays at the bottom of an early lake, leaving a very sticky hardpan extending to the approximate location of the Glacier Hills Service Plaza. The glacier created these and other foundation problems that harassed the builders of the Ohio Turnpike. The presence of rubbery blue till forced contractors to seek new means of finding substantial foundations for the roadways that must carry heavy traffic. Boulders lying beneath beds of streams hampered the building of piers to support turnpike bridges. Sinkholes, peat bogs and ancient riverbeds created further engineering problems. On the other hand the glacier helped turnpike construction by polishing off a fairly level landscape and depositing beds of debris that were used as borrow pits to provide material for necessary fills. The entire route of the Ohio Turnpike runs through areas covered by the glaciers, but the section in Mahoning County served by the Glacier Hills Service Plaza lies closest to the southernmost reaches of the last ancient ice flow.
There is a possibility that man had established himself in this region by the time the last glacier had receded. Ancient primitive tools, scrapers, hammers and spear points have been found in the glacial dirt and terraces at various points. It is possible that men were throwing spears around Ohio before the very last ice came because a few spear points appear to have come from beneath the top layer of glacial hardpan. If man was here, he dwelt in an evergreen forest and fought against great enemies including the mastodon, which resembled an elephant, with low, sloping forehead and long, upward curving tusks. Findings indicate that there were also giant musk oxen and beavers the size of bears.
It is possible, geologists say, that another great ice sheet may descend upon Ohio in another 80,000 or 90,000 years, since a period of approximately 100,000 years elapsed between each glacier, and it has been only 10,000 to 20,000 years since the last one. Then, probably, new “glacial hills” will make their appearance as features in a changed Ohio landscape.